What defines a wet vent in plumbing systems?

A wet vent is defined as a drainage pipe that also serves as a vent for the wastewater in a plumbing system. This dual function allows the pipe to carry both waste and air flow, which helps maintain proper drainage and prevents siphoning of traps in the system. The concept of wet venting is particularly useful in minimizing the number of pipes required in a plumbing installation, thereby simplifying the design and reducing material costs.

In systems where wet venting is utilized, the configuration typically permits a fixture’s drain to share the same pipe as the vent stack, as long as certain code requirements are met. This includes considerations like the size of the pipe and the number of fixtures served by the wet vent. By allowing for both drainage and venting, wet vents contribute to better overall system function by equalizing pressure and facilitating airflow.